1. Field of the Invention
The present invention relates to a segmental grinding wheel which is used in a grinding machine and the like.
2. Discussion of the Prior Art
Conventionally, a segmental grinding wheel is composed of a circular wheel core and a plurality of segmented grinding tips bonded on the peripheral surface of the wheel core through a bonding layer. Also, every two adjacent grinding tips are bonded to each other using bond.
When the segmental grinding wheel is rotated at a high speed, a large centrifugal force acts on the grinding chips. Therefore, the bonding strength between the wheel core and the grinding chips is very important in cases where the grinding wheel is rotated at a very high speed.
Further, since water-soluble epoxy resin is used as the bond in such segmental grinding wheel, the bonding layer thereof is gradually swelled by coolant during grinding operation, whereby the bonding strength of the bonding layer decreases gradually.
As a result, there is a limit on the rotational speed of the grinding wheel. Further, there is a problem that the service life of the grinding wheel becomes short due to the swelling of the bonding layer.